1. Field of the Invention
The present invention relates to a coaxial electrical connector in which an annular contact is attached to an insulating housing.
2. Description of Related Art
Generally, in various electrical devices, a pair of electrical connectors configured to be able to be mated/connected with each other has been widely used to electrically connect a signal transmission medium of various types such as a thin coaxial cable or a flexible wiring board to a printed wiring board or to electrically connect a pair of wiring boards (board to board) to each other. As such a pair of electrical connectors, for example, a plug connector (first connector), which is to be coupled to a signal transmission medium or a wiring board, and a receptacle connector (second connector), which is to be mounted on a wiring board, as described in Japanese Patent Application Laid-Open No. 2006-66384 are used; and electrical connection is configured to be established when the receptacle connector and the plug connector are mated with each other.
On the other hand, as the electrical connector used in connection of the above described pair of wiring boards (board to board) to each other, a coaxial electrical connector in which a contact is concentrically disposed is known. The coaxial electrical connector has a configuration in which an annular contact is attached to an insulating housing, and the annular contact is divided in a circumferential direction via a dividing slit provided at part in the circumferential direction of the annular contact. When mating or removal is to be carried out with a matching connector, the annular contact undergoes elastic deformation while divided end parts of the annular contact opposed to each other in the circumferential direction via the above described dividing slit are separated from each other in the circumferential direction, in other words, while the distance of the dividing slit is expanded. When the elastic deformation is carried out so as to increase the distance of the dividing slit of the annular contact in this manner, the outer diameter of the annular contact is somewhat expanded; however, at the point when the mating operation or the removing operation is completed, the annular contact is configured to recover to the original state so that both of the connectors are retained in a mated state or a released state.
However, recently, as reduction in the size/height of the electrical connectors has been advanced, the necessity of firmly retaining the annular contact at the insulating housing against removing force between there and the matching connector has been increasing. For example, Japanese Patent Application Laid-Open No. 2006-66384 employs a configuration in which an engagement projection 15 formed on an outer periphery of the insulating housing (plug body) is engaged with an opening formed in the annular contact (external conductor), and movement of the annular contact with respect to the insulating housing is configured to be regulated by such a configuration.
However, in the electrical connector disclosed in that document, the opening is formed in the annular contact (external conductor); therefore, the elasticity of the annular contact is varied depending on the shape and size of forming the opening, and the mating force or removing force between there and the matching connector is affected, the mating force or removing force with respect to the matching connector has to be adjusted so as to be appropriate as part of product performance. However, when the opening is provided in the annular contact in the above described manner, the shape and size of the opening have to be set depending on the relative relation with the material of a metal material constituting the annular contact. As a result, there has been a problem that it is difficult to cause the mating force or removing force with respect to the matching connector to be appropriate.
We disclose prior art that we are aware of to be materials for the examination of the application as follows.
[Unexamined Publication Gazette 1] JP 2006-66384 A